A restoration of J. P. Morgan's library illuminates lesser-known aspects of the collector and his treasures .

At a contentious meeting of bankers during the 1907 financial crisis, J. Pierpont Morgan locked the doors of his private library and study in New York’s Murray Hill, refusing to let his fellow financiers leave until they had agreed on a national-rescue plan. In that grand but intimate building, designed by Charles Follen McKim after an Italian Renaissance palazzo, Morgan also convened meetings of the acquisitions committee of the Metropolitan Museum of Art, of which he was president. After Morgan’s death, the building became the heart of the institution that for more than 80 years has made his collections available to the public. Now the Morgan Library & Museum, as it is known today, is restoring and reinstalling the rooms of his domain to better tell the story of its collections and the man behind them.

When the McKim building reopens on October 30, the North Room, originally the librarian’s office, will be accessible to the public for the first time. Visitors will also be able to peer inside Morgan’s vault. The interiors will be cleaned, the furniture restored, state-of-the-art lighting installed, and hundreds of additional objects placed on view. The refurbishment, which has closed the building since June, has cost $4.5 million.

“Throughout, we wanted to strike the right balance between period room and display space for the collections,” says the museum’s director, William M. Griswold, who underscores that moving more objects to the McKim building frees up valuable exhibition space in other parts of the museum.

Visitors will be able to see how the building functioned as a repository for Morgan’s collections. “Previously there was no way to understand that this was not Morgan’s house,” Griswold notes. Morgan had the library built adjacent to his home; an underground tunnel connected the two structures. But the buildings met different fates. Morgan’s house was dismantled and in 1928 replaced with an exhibition space and reading room, while the library, considered one of McKim’s masterpieces, has been left largely untouched—including in Renzo Piano’s 2006 expansion, which created a new entrance through a glass-roofed courtyard on Madison Avenue.

In Morgan’s day, visitors entered the library from 36th Street, stepping into a marble-clad rotunda. There, as in the library itself, they would find Henry Siddons Mowbray’s paintings on the ceiling (McKim persuaded Morgan to hire Mowbray by taking him to see the painter’s work at the University Club). The natural light previously admitted through the oculus would have harmed light-sensitive material. But the museum is turning the rotunda into exhibition space with new, safe lighting that will simulate natural light. Display cases will be dedicated to Morgan’s rarely seen Americana collection, including a life mask of George Washington, letters by Thomas Jefferson and Abraham Lincoln, and a copy of the Declaration of Independence.

The three-tiered library, with its cleaned stained-glass ceiling and new lighting, will glow like a jewel box. It previously functioned almost entirely as a period room, with less than a handful of objects on display. It will feature some 25 highlights from Morgan’s collection of books and manuscripts, including the Lindau Gospels, the finest jeweled Carolingian binding of the ninth century. In the archives, an 1899 Western Union cable from Morgan’s nephew Junius reveals—in a Latinate code—that the seller of the manuscript was asking £10,000. “Tambales solmites,” the telegram begins, translating as “can obtain for you.” (All of Morgan’s cables were coded, because his purchases could change a market in the span of a day.) The price proved too rich for the British Museum, but not for Morgan. His librarian labeled the acquisition “M1,” acknowledging its importance in a collection of 630 medieval and Renaissance illuminated manuscripts.

Morgan collected voraciously across centuries, countries, and genres, devoted to bringing the cultural treasures of the world to the American public. His wife, Fanny, said he would buy anything from a pyramid to Mary Magdalene’s tooth (in fact, he did buy a late-15th-century reliquary said to contain Mary Magdalene’s molar—it is now in the Met’s medieval galleries). The Chinese imperial family offered Morgan all of its treasures for $4 million, but he died before a deal could be made.

Yet while he often bought in blocks—as when he purchased an Oswego, New York, collector’s entire library, containing editions of the Iliad and the Odyssey printed in Florence in 1489—Morgan could be very selective. In one encounter in London, the dealer Joseph Duveen laid out 30 portrait miniatures; Morgan asked the price for the lot. Upon hearing it, he selected the best six items on the table and put them in his pocket. He then divided the figure by 30, multiplied it by six, and said that was the amount he would pay.

Morgan asked McKim to design the building to display books and illuminated manuscripts, as he owned more than 20,000 volumes. Following the renovations, nonreflective Plexiglas placed over the shelves in the library will permit visitors to read the spines of his books. But in the North Room, the bookcases will act as display cases to house Morgan’s substantial yet little-known collection of ancient and Near Eastern seals—most of which are one inch high—and tablets. “These were some of the first works Morgan bought and which fired his imagination from the time he was a teenager in the 1850s,” says Jennifer Tonkovich, the curator in charge of the reinstallation of collection objects. She has selected some 100 pieces for the room, including the unfired clay cuneiform tablet with the earliest known reference to the Flood. “He was very excited by archeological excavations, some of which he started funding in the early 20th century through the Met. This was brand-new material.”

Morgan’s personal study, with walls covered in red silk damask, reflected his self-fashioning as a modern-day Medici. It displayed Northern and Italian Renaissance paintings and sculpture, which Morgan collected with greater intensity after his retirement from Wall Street in 1907. After the renovation, the most visible change here will be the removal of a heavy curtain over the vault, where Morgan kept his most precious objects, such as the seventh-century illuminated manuscript the Golden Gospels of Henry VIII, written in gold letters on purple vellum, and thought to have been a gift from Pope Leo X.

“Morgan would sit in here and study these wonderful things he had acquired,” says Tonkovich, who is restaging the shelves with the original leather boxes that stored medieval manuscripts and setting up a small table with books and art objects. “It was every scholar’s dream. We want to re-create that feeling.”